(a) Technical Field
The present disclosure relates generally to a system and a method for controlling torque intervention, and more particularly, to a system and a method for controlling torque intervention of a hybrid electric vehicle for limiting driving force requested during the travelling of the vehicle.
(b) Background Art
As is generally known in the art, a hybrid electric vehicle is a vehicle equipped with a power train device and adopting an engine and a motor as power sources. The vehicle separately transmits power generated by the engine or the motor to a driving wheel or transmits power from both the engine and the motor to the driving wheel. Advantageously, the hybrid electric vehicle can decrease exhaust gas and improve fuel efficiency over conventional vehicles.
The power train device for the hybrid electric vehicle includes, for example, an engine clutch, which is arranged between the serially connected engine and motor to transmit or block power of the engine, and a transmission, which shifts and outputs the power of the motor or the power of the motor and the engine to the driving wheel. Meanwhile, the driving force (i.e., driving torque) generated during the driving of the vehicle can be limited by gear shifting and/or the brake. For example, the limitation of driving force by the gear shift can be requested by a transmission control unit (TCU), and the limitation of driving force by the brake can be requested by a brake control unit (BCU).
The TCU typically controls the transmission and prevents an excessive increase in engine speed or impact during the gear shift. The TCU can also request torque intervention for limiting the driving force to a hybrid control unit (HCU) which is a higher control unit for protecting the transmission and the like. The BCU, meanwhile, can control operation of the brake of the vehicle and can request torque intervention for limiting the driving force during the brake to the HCU. The HCU receives the request decreases and determines a torque of the engine and the motor based on a current torque.
In this case, the limitation of driving force requested by each control unit has a different purpose, but is the same in that the phenomena represented while driving is the torque decrease, and the respective control units are considerably similar in their functionality. However, technology for limiting driving force by the gear shift and technology for limiting driving force by the brake are separately developed according to the unit submitting the request (e.g., the TCU and the BCU). Consequently, resources such as time and money are wasted during the development process, and when duplicate requests for torque intervention are submitted by the gear shift and the brake, unintended results occur, including a poor response, deterioration of operation performance, and the like.
Therefore, in a case of a road surface during the winter season, covered in snow, ice, or the like, the limitation of driving force by the brake can be generated for a relatively long time, while an event for the gear shift is frequently generated during the limitation of the driving force by the brake. However, when a priority is given to the torque intervention by the brake, and the torque intervention by the gear shift is ignored, acceleration of the vehicle deteriorates due to a gear shift delay.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure. Therefore, it may contain information that does not form the related art that is already known to a person of ordinary skill in the art.